CN108879698B - Medium voltage distribution network double-ring topological structure comprising four-port flexible switch - Google Patents
Medium voltage distribution network double-ring topological structure comprising four-port flexible switch Download PDFInfo
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- CN108879698B CN108879698B CN201810825444.7A CN201810825444A CN108879698B CN 108879698 B CN108879698 B CN 108879698B CN 201810825444 A CN201810825444 A CN 201810825444A CN 108879698 B CN108879698 B CN 108879698B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/04—Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources
- H02J3/06—Controlling transfer of power between connected networks; Controlling sharing of load between connected networks
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
- H02G9/00—Installations of electric cables or lines in or on the ground or water
- H02G9/06—Installations of electric cables or lines in or on the ground or water in underground tubes or conduits; Tubes or conduits therefor
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
- H02G9/00—Installations of electric cables or lines in or on the ground or water
- H02G9/08—Installations of electric cables or lines in or on the ground or water in tunnels
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/28—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for meshed systems
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
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Abstract
The invention relates to a double-ring topology structure of a medium-voltage distribution network, which comprises a four-port flexible switch, and is characterized in that: the two-ring network topology structure module comprises a first ring network topology structure module, a second ring network topology structure module, a first power supply, a second power supply, a fourth power supply and a fourth power supply module; the power supply input end of the first ring network topology structure module is respectively connected with the first power supply, and the power supply output end of the first ring network topology structure module is connected with the first alternating current port and the second alternating current port of the four-port flexible-straight module; the power supply input end of the second ring network topological structure module is respectively connected with the second power supply, and the power supply output end of the second ring network topological structure module is connected with the third and fourth alternating current ports of the four-port flexible-straight module; and the load ends of the first and second ring network topological structure modules are connected with the user end. The method can be widely applied to the field of design of the medium-voltage distribution network with high reliability.
Description
Technical Field
The invention belongs to the field of planning and design of power distribution networks, and particularly relates to a double-ring topology structure of a medium-voltage power distribution network, which is suitable for a high-reliability power supply area and comprises a four-port flexible switch.
Background
The power distribution network is a key link in an electric energy supply chain for connecting power grid enterprises and terminal users, and is an important carrier for ensuring energy supply safety, realizing economic benefit and showing social responsibility and high-quality service level of the power grid enterprises. At present, a medium-voltage distribution network in a domestic high-reliability power supply area is mainly provided with a cable ring network, a topological structure comprises a cable single-ring network, a double-ring network and n supply 1, and the planning, construction and operation of the medium-voltage distribution network mainly adopt a strategy of 'ring network construction and open-loop operation'. Compared with the power supply reliability level of about 5 minutes of power failure time of all households in developed countries and areas such as Tokyo, Singapore, Paris and the like abroad, the power supply reliability level of the power distribution network in areas with high reliability power supply requirements in China has a large gap.
Along with the popularization of distributed clean energy power generation such as photovoltaic power generation and power generation at an energy production end and the development of diversified loads such as electric automobiles, electric heating and energy storage at an energy consumption end, a power distribution network is changed from passive to active, and tide is changed from unidirectional to bidirectional. The active power of the distributed power supplies such as photovoltaic power, wind power and the like is greatly influenced by environmental climate, the controllability is poor, and the immediacy is strong; the diversified loads with the energy storage characteristic represented by electric automobiles are strongly related to the behavior characteristic of users, the randomness of the power utilization loads is strong, the operation characteristics of V1G and V2G are variable, and the power distribution network is undergoing unprecedented historical revolution. The topological structure design is the basis for planning and constructing the power distribution network, and flexibly and efficiently accommodating distributed power supplies and diversified loads becomes the problem and focus of the current power distribution network topological structure design. The development of the power electronic technology injects new vitality into the development of a power distribution network, the development of the flexible direct current power transmission and distribution technology is changed day by day, a series of devices such as a power electronic transformer, a flexible switch, a dynamic voltage restorer and the like are demonstrated and applied to the power distribution network, and good application cases are obtained in the aspects of power distribution network structure transformation, active power control, reactive voltage regulation and the like.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a medium voltage distribution network double-ring topology structure including a four-port flexible switch, where the medium voltage distribution network double-ring topology structure is suitable for areas with high load density and high reliability requirements, and the medium voltage distribution network double-ring topology structure includes a 10kV distribution network double-ring topology structure including a four-port flexible switch device, a network internal device configuration standard, a network station room channel facility construction standard, and a protection configuration scheme, so as to implement flexible and controllable closed-loop operation and power of a 10kV network, and achieve an average availability of the system exceeding 99.9999%, and simultaneously adapt to load access of a distributed power supply and an electric vehicle.
In order to achieve the purpose, the invention adopts the following technical scheme: the utility model provides a medium voltage distribution network dicyclo topological structure who contains four port flexible switch which characterized in that: the two-ring network topology structure module comprises a first ring network topology structure module, a second ring network topology structure module, a first power supply, a second power supply, a fourth power supply and a fourth power supply module; the power supply input end of the first ring network topology structure module is respectively connected with the first power supply, and the power supply output end of the first ring network topology structure module is connected with the first alternating current port and the second alternating current port of the four-port flexible-straight module; the power supply input end of the second ring network topological structure module is respectively connected with the second power supply, and the power supply output end of the second ring network topological structure module is connected with the third and fourth alternating current ports of the four-port flexible-straight module; and the load ends of the first and second ring network topological structure modules are connected with the user end.
The first and second ring network topological structure modules have the same structure and respectively comprise more than one power distribution module and more than two pairs of cable modules, and each pair of cable modules are looped in or out of each power distribution module in a double-loop mode.
Each power distribution module is connected in series, the power distribution module positioned at the forefront end serves as a power supply input end of the first or second ring network topology structure module, two return wires in the power distribution module are respectively connected with the first or second power supply through the cable module, and two return wires are respectively connected with a next-level power distribution module through the cable module; the power distribution module at the tail end serves as a power output end of the first or second ring network topological structure module, two return wires in the power distribution module are respectively connected with a superior power distribution module through the cable module, and two return feeders are respectively connected with the four-port flexible straight module through the cable module; two return wires and feeder lines in other distribution modules are respectively connected with upper and lower distribution modules through the cable modules to form a series structure; and the outgoing line of each distribution module is used as a load end of the ring network topology structure module and is connected with the user end.
The power distribution module adopts any one of a switch station, a ring network chamber or a power distribution chamber, the switch station is arranged in 10kV metal armor in a withdrawable switch cabinet group screen, the ring network chamber and the power distribution chamber are arranged in a ring network cabinet group screen, and the short-circuit current interruption capacity level of the withdrawable switch cabinet and the ring network cabinet equipment in the 10kV metal armor is not less than 20 kA.
The primary main connection wire of the switch station comprises a 10kV I section bus and a 10kV II section bus, two sections of 10kV independent buses, and each independent bus is provided with a voltage transformer cabinet, two incoming line cabinets and a plurality of feeder cabinets; the two first incoming line cabinets on the section I bus and the section II bus are used as two return lines of a power distribution module and are respectively connected with the power supply or an upper-level power distribution module thereof, and the two second incoming line cabinets on the section I bus and the section II bus are used as two return lines of the power distribution module and are respectively connected with a lower-level power distribution module or a four-end flexible straight module thereof; feeder cabinets on the I section bus and the II section bus are used as outgoing lines and are respectively connected with the user side.
The primary main wiring of the ring network room comprises a 10kV I section bus and a 10kV II section bus, two sections of 10kV independent buses, and each independent bus is provided with a voltage transformer cabinet, a first incoming line cabinet, a second incoming line cabinet, a sectional cabinet and a plurality of feeder cabinets; two first incoming line cabinets on the 10kV I-section bus and the 10kV II-section bus as two incoming lines of a power distribution module are respectively connected with the power supply or the power distribution module at the upper stage of the power supply, and two second incoming line cabinets on the 10kV I-section bus and the 10kV II-section bus as two feeder lines of the power distribution module are respectively connected with the power distribution module at the lower stage or the four-end flexible straight module; feeder cabinets on the 10kV I section bus and the 10kV II section bus are used as outgoing lines and are respectively connected with the user side.
The primary main wiring of the distribution room comprises two sections of 10kV independent buses, namely a 10kV I section bus and a 10kV II section bus, and four sections of 0.4kV I section bus, 0.4kV II section bus, 0.4kV III section bus and 0.4kV IV section bus, namely 0.4kV independent bus; each section of the 10kV independent bus is provided with two transformer cabinets, an incoming line cabinet and a feeder line cabinet; the two incoming line cabinets on the 10kV I-section bus and the 10kV II-section bus are used as two incoming lines of a power distribution module and are respectively connected with the power supply or an upper-level power distribution module thereof, and the two feeder line cabinets on the 10kV I-section bus and the 10kV II-section bus are used as two feeder lines of the power distribution module and are respectively connected with a lower-level power distribution module or the four-end flexible straight module thereof; the two transformer cabinets are respectively connected with the 0.4kV independent bus to supply power to the 0.4kV independent bus; each section of the 0.4kV independent bus is provided with an incoming line main cabinet, a capacitor cabinet, an outgoing line cabinet and a contact cabinet; the contact cabinet of the 0.4kV I-section bus is connected with the 0.4kV II-section bus to form a group, the incoming line main cabinet of the 0.4kV I-section bus is connected with the transformer 1 cabinet of the 10kV I-section bus of the distribution room, and the incoming line main cabinet of the 0.4kV II-section bus is connected with the transformer 2 cabinet of the 10kV II-section bus; the contact cabinet of the 0.4kV section III bus is connected with the 0.4kV section IV bus to form a group, the incoming line main cabinet of the 0.4kV section III bus is connected with the transformer 3 cabinet of the 10kV section I bus in the distribution room, and the incoming line main cabinet of the 0.4kV section II bus is connected with the transformer 4 cabinet of the 10kV section II bus; and the outgoing line cabinet of each 0.4kV independent bus is connected with the user side.
The cable module adopts a crosslinked polyethylene insulated polyvinyl chloride sheath power cable, the material of the cable conductor adopts a copper conductor, the cable insulation shield or the metal sheath adopts a soft copper wire or a copper strip, the cable core has 3 cores, and the cross section comprises 300mm2And 400mm2The laying mode comprises a calandria and a cable tunnel.
The calandria laying mode is as follows: tamping raw soil at the bottom of the pipe, paving a C15 concrete bottom plate on the pipe, arranging the calandria on the bottom plate side by side, arranging a communication pipe between every two calandrias at one side of the two calandrias, backfilling the calandria by fine sand, and arranging a warning belt on the piping; the cable tunnel laying mode is as follows: the method comprises the steps of excavating a cable tunnel clearly, arranging two side brackets in the cable tunnel, wherein each side bracket comprises a plurality of layers of cable brackets, embedded parts and an inner connection zone, wherein each layer of cable bracket is connected with each embedded part through bolts, and the inner connection zone is connected with each layer of cable bracket and is grounded.
The four-port flexible direct module adopts a screen cabinet type IGBT valve body, comprises four groups of first-fourth combined modularized multi-level AC-DC converters connected in pairs and four groups of DC breakers arranged between the two groups of modularized multi-level AC-DC converters, the AC ports of the first modularized multi-level AC-DC converter and the second modularized multi-level AC-DC converter are used as the first and second AC ports of the four-port flexible direct module to be connected with the power output end of the first ring network topological structure module, and the AC ports of the second modularized multi-level AC-DC converter and the third modularized multi-level AC-DC converter are used as the third and fourth AC ports of the four-port flexible direct module to be connected with the power output end of the second ring network topological structure module.
Due to the adoption of the technical scheme, the invention has the following advantages: 1. according to the invention, the two ring network topological structure modules are matched with the four-port flexible straight module, so that the high-load-density flexible straight module can adapt to the high-load-density level and high-reliability power supply requirements, has the technical conditions of long-term closed-loop operation, has the fault of any cable line, does not lose the power supply load, has the reliability level of 99.9999%, and provides a continuous power supply capability with the power failure time of less than 1 minute for a user; 2. because the four-port flexible direct-current switch equipment is included, a direct-current power distribution network can be networked with a traditional alternating-current power distribution network, a high-voltage alternating-current and direct-current ring network and low-voltage side alternating-current and direct-current flexible interconnection are realized, closed-loop operation is realized, active and reactive power is continuously controlled and adjusted, and the short-circuit current of the system after the closed-loop operation is effectively controlled, so that the equipment model selection is facilitated; 3. the invention adopts a modular design scheme, integrates the equipment model selection and miniaturization, can be more suitable for the problem of short land use in a high-reliability power supply area, has unified equipment model selection and construction standards, and further improves the engineering design quality and efficiency. 4. The user side of the invention can meet the diversified power supply and consumption requirements of users with diversified loads accessed by distributed power supplies, electric automobile charging and replacing facilities and the like, thereby improving the reliability and flexibility of power supply of the power distribution network, improving the efficiency of the power distribution network and improving the quality of electric energy. Therefore, the invention can be widely applied to the construction of medium-voltage distribution networks.
Drawings
FIG. 1 is a schematic diagram of a dual-ring topology of a high-reliability power distribution network according to the present invention;
fig. 2(a), 2(b) are diagrams of the distribution module switchyard scheme 10kV system configuration of the present invention;
fig. 3(a) and 3(b) are configuration diagrams of a power distribution module ring network room scheme 10kV system of the invention;
FIG. 4 is a diagram of the power distribution module room scheme main wiring of the present invention;
FIG. 5 is a schematic view of a gauntlet arrangement in a cable module according to the invention;
fig. 6 is a schematic view of a tunneling scheme in a cable module of the present invention;
FIG. 7 is a schematic diagram of normal operation of the dual-ring topology distribution network of the present invention;
FIG. 8 is an example of a high reliability distribution network dual ring topology customer distribution room of the present invention;
FIG. 9 is a schematic view of the overhaul operation of the 10kV incoming line loop of the power distribution module of the present invention;
FIG. 10 is a schematic view of the overhaul operation of the 10kV outgoing line loop of the power distribution module of the present invention;
FIG. 11 is a schematic diagram of the distribution module 10kV outgoing line loop maintenance user low-voltage load transfer;
FIG. 12 is a schematic view of the overhaul operation of the 10kV bus of the power distribution module of the present invention;
FIG. 13 is a schematic diagram of the invention distribution module 10kV bus fault/service user low voltage load transfer;
FIG. 14 is a schematic diagram of the single bus fault/repair of a superior substation of the present invention;
FIG. 15 is a schematic view of the shutdown and overhaul of the whole upper-level substation of the present invention;
fig. 16 is a main circuit structural view of the four-port flexible switching device of the present invention.
Detailed Description
The invention is described in detail below with reference to the figures and examples.
As shown in fig. 1, the present invention provides a double-ring topology structure of a medium voltage distribution network including a four-port flexible switch, which includes: the system comprises first and second two-ring network topological structure modules 1-2, first and second two transformer substations 3-4 and a four-port flexible-straight module 5. The first and second alternating current ports of the four-port flexible-straight module 5 are connected with the power output end of the first ring network topology structure module 1, and the third and fourth alternating current ports of the four-port flexible-straight module 5 are connected with the power output end of the second ring network topology structure cable module 2; the power input end of the first ring network topological structure module 1 is respectively connected with the two buses 31 and 32 of the first transformer substation 3, and the power input end of the second ring network topological structure module 2 is respectively connected with the two buses 41 and 42 of the second transformer substation 4; the load ends of the first and second ring network topology structure modules 1 and 2 are connected with a user end formed by equipment such as a user power distribution room, a distributed power supply, an electric automobile and a charging and switching facility. The first transformer substation 3, the second transformer substation 4 and the third transformer substation serve as power supplies, and power is supplied to the double-ring network topology structure through different 10kV buses or different 10kV switch stations.
The first and second ring network topological structure modules 1 and 2 have the same structure and respectively comprise a plurality of power distribution modules and a plurality of cable modules, and different buses in the power distribution modules are looped in (looped out) by the double-loop cable modules in the network. Taking the first ring network topology structure module 1 as an example, specifically, all the power distribution modules are connected in series, wherein the power distribution module at the forefront end is taken as a power input end of the first ring network topology structure module 1, two return incoming lines in the power distribution module are respectively connected with the first transformer substation 3 through cable modules, and two return feeder lines are respectively connected with a lower-level power distribution module through cable modules; the power distribution module at the tail end serves as a power output end of the ring network topological structure module, two return wires in the power distribution module are respectively connected with a superior power distribution module through cable modules, and two return feeders are respectively connected with the four-port flexible and straight module 5 through the cable modules; two return wires and feeder lines in other distribution modules are respectively connected with upper and lower distribution modules through cable modules to form a series structure; the outgoing line of each power distribution module is used as the load end of the first ring network topology structure module 1 and is connected with the user end.
As shown in fig. 2 to 4, each power distribution module adopts any one of a switch station, a looped network room or a power distribution room, and the type and the number are determined according to actual needs. The switch station is provided with a removable switch cabinet group screen in 10kV metal armor, the ring network chamber and the distribution chamber are provided with a ring main unit group screen, and the short-circuit current interruption capacity level of the removable switch cabinet and the ring main unit equipment in the 10kV metal armor is not less than 20 kA. The structures of the switching station, the ring network room and the distribution room are described as follows:
as shown in fig. 2, in the switching station, the primary main connection line includes two 10kV independent buses, i.e. a 10kV bus and II 10kV bus, and a voltage transformer cabinet G1(G18), a first incoming line cabinet G2(G16), a second incoming line cabinet G3(G17) and a plurality of feeder cabinets G4-9 (G10-15) are disposed on the I10 kV bus and II 10kV bus (the invention is only described by taking 6 groups of feeder cabinets as an example, but not limited thereto). The two second wire inlet cabinets G3 and G17 on the I section bus and the II section bus are used as two feedback wires of the power distribution module and are respectively connected with the lower-level power distribution module or the four-terminal flexible straight module 5 of the power distribution module; feeder cabinets G4-9 and G10-15 on the I section bus and the II section bus are respectively connected with the user side as outgoing lines.
The specific configuration standards of the cabinets in the switchyard are shown in table 1 below.
TABLE 1 concrete configuration standards for cabinets in a switchgear station
As shown in fig. 3, in the ring network room, the primary main connection line includes two 10kV independent buses, i.e. a 10kV I-section bus and a 10kV II-section bus, and each independent bus is provided with a voltage transformer cabinet G1(G20), a first incoming line cabinet G2(G13), a second two incoming line cabinet G8(G19), a segment cabinet G10(G11), and a plurality of feeder cabinets G3-7 (G14-18) (in the invention, only 5 groups of feeder cabinets are taken as an example for description, but not limited thereto). The two first incoming line cabinets G2 and G13 on the 10kV I section bus and the 10kV II section bus are used as two incoming lines of a power distribution module and are respectively connected with a transformer substation 1 (namely, a first-end power distribution module is connected with the transformer substation) or an upper-level power distribution module thereof (namely, a middle power distribution module is connected with an upper-level power distribution module thereof), and the two second incoming line cabinets G8 and G19 on the 10kV I section bus and the 10kV II section bus are used as two incoming lines of the power distribution module and are respectively connected with a lower-level power distribution module or a four-end flexible straight module thereof; feeder cabinets G3-7 and G14-18 on the 10kV I section bus and the 10kV II section bus are used as outgoing lines and are respectively connected with the user side. The sectional cabinets G10 and G11 generally comprise two sectional cabinets, wherein one sectional cabinet is used for connecting the buses below the cabinet through the circuit breaker, and the other sectional cabinet is used for connecting the I-section buses and the II-section buses and is used by being divided into two sections or combined into one section according to the operation requirement.
The specific configuration standards of the cabinets in the ring network room are shown in table 2 below.
TABLE 2 concrete configuration standards of cabinets in the ring network room
As shown in fig. 4, the distribution room includes two 10kV independent buses and four 0.4kV independent buses of a 10kV I-section bus and a 10kV II-section bus, and each 10kV independent bus is respectively provided with a voltage transformer cabinet G1, a G2, two transformer cabinets G3-G4, a G5-G6, a line inlet cabinet G7, a G8, and a feeder cabinet G9, a G10; the two feeder cabinets G7 and G8 on the 10kV I section bus and the 10kV II section bus are used as two return inlet wires of a power distribution module and are respectively connected with a transformer substation 1 (namely a first-end power distribution module is connected with the transformer substation) or an upper-level power distribution module thereof (namely a middle power distribution module is connected with an upper-level power distribution module thereof), and the two feeder cabinets G9 and G10 on the 10kV I section bus and the 10kV II section bus are used as two return feeder wires of the power distribution module and are respectively connected with a lower-level power distribution module or a four-end flexible straight module thereof; the transformer cabinets G3-G6 are respectively connected with 0.4kV independent buses to supply power for the buses.
Each section of 0.4kV independent bus is provided with an incoming line main cabinet G11-14, a capacitor cabinet G15-18 and a plurality of outgoing line cabinets, a 0.4kV I section bus is provided with an interconnection cabinet G19, and a 0.4kV III section bus is provided with an interconnection cabinet G20. The interconnection cabinet G19 of the 0.4kV I-section bus is connected with the 0.4kV II-section bus to form a group, the incoming line main cabinet G11 of the 0.4kV I-section bus is connected with the transformer cabinet G3 of the 10kV I-section bus of the distribution room, and the incoming line main cabinet G12 of the 0.4kV II-section bus is connected with the transformer cabinet G5 of the 10kV II-section bus; similarly, a contact cabinet G20 of a 0.4kV section III bus is connected with a 0.4kV section IV bus to form a group, an incoming line main cabinet G13 of the 0.4kV section III bus is connected with a transformer cabinet G4 of a 10kV section I bus in a distribution room, and an incoming line main cabinet G14 of the 0.4kV section II bus is connected with a transformer cabinet G6 of a 10kV section II bus; and the outgoing line cabinet on each 0.4kV independent bus is connected with the user side.
According to the structural introduction of the switch station, the ring network room and the distribution room, the various facility characteristics are as shown in table 3 below.
TABLE 3 comparison table for various facilities and characteristics of distribution module
As a preferred embodiment, each power distribution module 11 is further provided with a protection configuration device, specifically including an optical fiber longitudinal differential protection and a multi-load protection for incoming (outgoing) lines of a switching station, a looped network room and a power distribution room, a line current quick-break protection and an overload protection device provided on a feeder cabinet, a looped network protection device provided on each section of independent bus, and a bus differential protection device. Since the protection arrangements are conventional and the structural design in the present invention only involves the electrical primary part, the protection arrangements are not shown in the figures.
As a preferred embodiment, the cable module 12 is a cross-linked polyethylene insulated polyvinyl chloride sheathed power cable, the material of the cable conductor is a copper conductor, the material of the cable insulation shield or the metal sheath is a soft copper wire or a copper strip, the cable core is 3 cores, and the section of the cable core comprises 300mm2And 400mm2The laying mode comprises a calandria and a cable tunnel.
Fig. 5 is a schematic cross-sectional view of 4 × 4 rows of tubes, wherein the tube pitch is 75mm, and communication tubes with an inner diameter of 100mm are placed on the left side between the first row of tubes and the second row of tubes, and between the third row of tubes and the fourth row of tubes. The bottom of the pipe is compacted by adopting raw soil, and a C15 concrete bottom plate is paved on the pipe. And fine sand is used for backfilling among the pipes. The piping is provided with a warning belt. In fig. 5, the inner diameter of the gauntlet tube is 175mm for example, and when the inner diameter of the gauntlet tube is 150mm or 200mm, the corresponding adjustment should be made, and the adjustment parameters are shown in table 4 below.
Watch 4 different tube inner diameter adjusting size meter (mm)
Fig. 6 shows a cable tunnel support layout of a double-sided 6-layer support. The cable tunnel is an open excavation 2.0m multiplied by 2.1m cable tunnel, and the soil covering depth is 0.7-2.0 m. The supports in the tunnel are arranged on two sides, and the horizontal distance is 800 mm. In the figure, firstly, the cable support is provided with 6 layers on both sides in the tunnel, the width of the support is 500mm, and the distance between the upper layer support and the lower layer support is 0.3 m. And the second in the figure is an embedded part which is connected by a bolt. In the figure, the third is the inscribed zone with the model of-50 mm multiplied by 5 mm. In the figure, the illumination system is designated by r.
Fig. 7 is a schematic diagram of the main circuit of the four-port flexible switching device 5. The four-port flexible straight module 5 adopts a screen cabinet type IGBT valve body, a topological structure adopts a voltage source converter of a half-bridge type modular multilevel structure, and the power of the converter is about 40 MW. The control strategy comprises three kinds of control of fixed direct-current voltage, reactive power control at an alternating-current side and active power control. Specifically, the four-port flexible switch equipment comprises four groups of modular multilevel AC-DC converters 1-4 and four groups of DC breakers k 1-k 4 arranged between every two converters, wherein AC ports of the converters 1-2 are used as first and second AC ports of a four-port flexible-DC module to be connected with a power output end of a first ring network topological structure module, and AC ports of the converters 3-4 are used as third and fourth AC ports of the four-port flexible-DC module to be connected with a power output end of a second ring network topological structure module. By operating the direct current breakers k 1-k 4, the four-port flexible switch device can realize the following working states:
working state 1: closing the direct current circuit breakers k1 and k2, and simultaneously opening the direct current circuit breakers k3 and k4 to realize flexible interconnection between port alternating current 1 and alternating current 2 and flexible interconnection between alternating current 3 and alternating current 4;
and 2, working state: closing the direct current circuit breakers k3 and k4, and simultaneously opening the direct current circuit breakers k1 and k2 to realize flexible interconnection between port alternating current 1 and alternating current 3 and flexible interconnection between alternating current 2 and alternating current 4;
and 3, working state: closing the direct current circuit breakers k1 and k3, and opening the direct current circuit breakers k2 and k4 to realize flexible interconnection among ports, namely alternating current 1, alternating current 2 and alternating current 3;
and the working state 4: closing the direct current circuit breakers k2 and k4, and opening the direct current circuit breakers k1 and k3 to realize flexible interconnection among ports of alternating current 2, alternating current 3 and alternating current 4;
and (5) working state: closing the direct current circuit breakers k1, k3 and k4, and opening the direct current circuit breaker k2 to realize flexible interconnection among port alternating currents 1, 2, 3 and 4;
the working state 6: and closing the direct current breakers k2, k3 and k4, and opening the direct current breaker k1 to realize flexible interconnection among the port alternating currents 1, 2, 3 and 4.
The working state of the four-port flexible switch equipment can be divided into three control strategies, the first type is constant direct-current voltage control (corresponding to the working state 1), the main function of the four-port flexible switch equipment is to maintain the direct-current voltage of a direct-current system to be constant, and the direct-current voltage control side plays a role of a power balance node; the second type is alternating current side reactive power control and alternating current voltage control (corresponding to a working state 2), active power transmission is considered, and reactive power output is limited by a PQ operation curve of the station; and in the third type of active power control (corresponding to working states 3-6), an active power curve instruction is preset. The loop closing (opening) operation of different buses, the power distribution of the feeder line and the load flow optimization can be realized through a control strategy.
The operation mode of the invention comprises the following steps: the normal operation mode and the maintenance operation mode are described in detail below.
1. Normal operation mode
As can be seen from the network topology structure shown in fig. 1, the dual-ring topology structure of the present invention uses four-loop cable lines as a set of standard structure, the power supply is taken from different 10kV buses of two substations or different 10kV switchyard buses, the dual-loop cable modules in the network are looped into (looped out) different buses in the power distribution module, four-port feeder interconnection is realized between networks through the four-port flexible-straight module, and the buses of the power distribution module in the network provide power for users, distributed power supplies, charging and switching facilities, etc.
As shown in fig. 8, in a normal operation mode, a user accessing to a dual-ring topology structure of a power distribution network usually determines a power supply scheme according to a first-level load, and is powered by dual power sources, and a higher-level power source is from two buses of the same substation, and the four buses are connected through a four-port flexible-straight module to form two closed loops. The maximum power supply capacity of the double-ring network structure can reach about 40MW, load transfer under the condition of any feeder line fault is considered, and the maximum access load of the double-ring network can reach about 30MW under the condition of a normal operation mode.
At the moment, the four-port flexible switch device works in a state 1, a control strategy of the current converter is selected by combining the voltage level of the alternating current system and the feeder power on the outlet side of the substation bus, the feeder power on the outlet side of the substation bus is ensured to be balanced, and the voltage level of the alternating current bus connected with the distributed power supply meets the operation requirement.
As shown in fig. 9, in order to improve the power supply reliability, the user distribution room adopts a low-voltage bus connection mode, specifically, the user distribution room includes two 400V buses, a bus tie breaker is arranged between the two 400V buses, the incoming lines of the two 400V buses are respectively connected with a switch station in the distribution module, or a ring network room, or a feeder cabinet connected with an independent bus in the distribution room, the distribution module provides a power supply, the outgoing line side of the first 400V bus is provided with a general load, an important load, and an emergency power supply for ensuring the power consumption of the important load, and the outgoing line side of the second 400V bus is provided with an important load and a general load. When the bus-bar circuit breaker normally operates, the low-voltage bus-bar operates separately, and the bus-bar circuit breaker is in a hot standby state. When the distribution room is in line incoming and the transformer is in fault or overhauled, the bus-tie breaker is closed to realize low-voltage load transfer.
2. And (3) maintenance operation mode:
when the cable line has a fault condition, the switch equipment connected with the bus at two ends of the cable line acts on the optical fiber longitudinal differential protection, the cable line quits from running, the fault is isolated, and the load power supply in the network is not influenced by the line fault; when a feed-out line of a switching station or a ring network room has a fault, a line protection device of a feed-out line cabinet acts to trip off a circuit breaker of a feeder line of the local circuit, and a fault feeder line is cut out from a network; when any switch station (ring network room) bus in the ring network has a fault, the bus protection device acts, and all circuit breakers related to the fault bus are tripped.
According to different maintenance equipment, the maintenance of a 10kV incoming line loop of the power distribution module, the maintenance of a 10kV outgoing line loop of the power distribution module, the maintenance of a 10kV bus of the power distribution module, the fault/maintenance of a single bus of a higher-level transformer substation and the shutdown of the whole station of the higher-level transformer substation can be divided.
(1) Distribution module 10kV inlet wire loop overhaul
As shown in fig. 10, a schematic diagram of a 10kV incoming line loop overhaul of a power distribution module (a switch station, a ring main room or a power distribution room). When the 10kV incoming line loop of the power distribution module is overhauled, circuit breakers at two ends of a fault line need to be disconnected.
(2) Distribution module 10kV outgoing line loop overhaul
As shown in fig. 11 and 12, the overhaul schematic diagram of the 10kV outgoing line loop of the power distribution module is shown. When the distribution module 10kV is subjected to loop maintenance, the distribution module outgoing line side and the user side distribution room incoming line power supply circuit breaker need to be disconnected. And closing a low-voltage bus tie breaker in a user power distribution room to realize load transfer.
(3) 10kV bus overhaul of power distribution module
As shown in fig. 13 and 14, the overhaul of the 10kV bus of the power distribution module is performed in a half-station full stop mode, and all incoming and outgoing line power circuit breakers and opposite side circuit breakers of the bus need to be disconnected or planned to be overhauled. And closing the low-voltage bus coupler circuit breaker of the user distribution room to realize load transfer.
(4) Single bus fault/overhaul of higher-level substation
As shown in fig. 15, in the process of repairing a single bus of an upper-level substation, attention needs to be paid to sequential loop closing and load reversing operations (first closing a bus tie breaker and then opening a line breaker) according to a clockwise or counterclockwise sequence.
(5) Whole station of higher level transformer substation stops transporting
As shown in fig. 16, when the whole substation of the upper-level substation is shut down, for example, when the whole substation of the substation 1 is shut down, the four-port flexible-straight module operates in the state 6 to connect the four lines, and the substation 2 forms a loop-closing operation.
The above embodiments are only used for illustrating the present invention, and the structure, connection mode, manufacturing process, etc. of the components may be changed, and all equivalent changes and modifications performed on the basis of the technical solution of the present invention should not be excluded from the protection scope of the present invention.
Claims (8)
1. The utility model provides a medium voltage distribution network dicyclo topological structure who contains four port flexible switch which characterized in that: the two-ring network topology structure module comprises a first ring network topology structure module, a second ring network topology structure module, a first power supply, a second power supply, a fourth power supply and a fourth power supply module;
the power supply input end of the first ring network topology structure module is respectively connected with the first power supply, and the power supply output end of the first ring network topology structure module is connected with the first alternating current port and the second alternating current port of the four-port flexible-straight module;
the power supply input end of the second ring network topological structure module is respectively connected with the second power supply, and the power supply output end of the second ring network topological structure module is connected with the third and fourth alternating current ports of the four-port flexible-straight module;
the load ends of the first and second ring network topological structure modules are connected with the user end; the user side comprises a user power distribution room, a distributed power supply, an electric automobile and a charging and battery replacing facility;
the first and second ring network topological structure modules have the same structure and respectively comprise more than one power distribution module and more than two pairs of cable modules, and each pair of cable modules are looped in or out of each power distribution module in a double-loop manner;
the four-port flexible direct-current module adopts a screen cabinet type IGBT valve body and comprises four groups of modularized multi-level AC-DC converters connected in pairs, four groups of DC breakers arranged between every two modularized multi-level AC-DC converters, a first group of DC breakers are arranged between the first modularized multi-level AC-DC converter and the second modularized multi-level AC-DC converter, a second group of DC breakers are arranged between the third modularized multi-level AC-DC converter and the fourth modularized multi-level AC-DC converter, a third group of DC breakers are arranged between the first modularized multi-level AC-DC converter and the third modularized multi-level AC-DC converter, and a fourth group of DC breakers are arranged between the second modularized multi-level AC-DC converter and the fourth modularized multi-level AC-DC converter; alternating current ports of the first modular multilevel AC-DC converter and the second modular multilevel AC-DC converter are used as first alternating current ports and second alternating current ports of the four-port flexible-DC module to be connected with a power output end of the first ring topology module, and alternating current ports of the second modular multilevel AC-DC converter and the third modular multilevel AC-DC converter are used as third alternating current ports and fourth alternating current ports of the four-port flexible-DC module to be connected with a power output end of the second ring topology module;
user's electricity distribution room adopts low pressure generating line contact, including two 400V generating lines, two set up female circuit breaker that allies oneself with between the 400V generating line, two the inlet wire side of 400V generating line respectively with the distribution module links to each other, by the distribution module provides the power, one of them the side of being qualified for the next round of competitions of 400V generating line sets up conventional load, important load and is used for guaranteeing the emergency power source of important load power consumption, another the side of being qualified for the next round of competitions of 400V generating line sets up important load and conventional load.
2. The dual ring topology of a medium voltage distribution network comprising a four-port flexible switch according to claim 1, wherein: each power distribution module is connected in series, the power distribution module positioned at the forefront end serves as a power supply input end of the first or second ring network topology structure module, two return wires in the power distribution module are respectively connected with the first or second power supply through the cable module, and two return wires are respectively connected with a next-level power distribution module through the cable module;
the power distribution module at the tail end serves as a power output end of the first or second ring network topological structure module, two return wires in the power distribution module are respectively connected with a superior power distribution module through the cable module, and two return feeders are respectively connected with the four-port flexible straight module through the cable module;
two return wires and feeder lines in other distribution modules are respectively connected with upper and lower distribution modules through the cable modules to form a series structure;
and the outgoing line of each distribution module is used as a load end of the ring network topology structure module and is connected with the user end.
3. The dual ring topology of a medium voltage distribution network comprising a four-port flexible switch according to claim 1, wherein: the power distribution module adopts any one of a switch station, a ring network chamber or a power distribution chamber, the switch station is arranged in 10kV metal armor in a withdrawable switch cabinet group screen, the ring network chamber and the power distribution chamber are arranged in a ring network cabinet group screen, and the short-circuit current interruption capacity level of the withdrawable switch cabinet and the ring network cabinet equipment in the 10kV metal armor is not less than 20 kA.
4. A medium voltage distribution network double loop topology comprising four port flexible switches according to claim 3, characterized in that: the primary main connection wire of the switch station comprises a 10kV I section bus and a 10kV II section bus, two sections of 10kV independent buses, and each independent bus is provided with a voltage transformer cabinet, two incoming line cabinets and a plurality of feeder cabinets;
the two first incoming line cabinets on the section I bus and the section II bus are used as two return lines of a power distribution module and are respectively connected with the power supply or an upper-level power distribution module thereof, and the two second incoming line cabinets on the section I bus and the section II bus are used as two return lines of the power distribution module and are respectively connected with a lower-level power distribution module or a four-end flexible straight module thereof; feeder cabinets on the I section bus and the II section bus are used as outgoing lines and are respectively connected with the user side.
5. A medium voltage distribution network double loop topology comprising four port flexible switches according to claim 3, characterized in that: the primary main wiring of the ring network room comprises a 10kV I section bus and a 10kV II section bus, two sections of 10kV independent buses, and each independent bus is provided with a voltage transformer cabinet, a first incoming line cabinet, a second incoming line cabinet, a sectional cabinet and a plurality of feeder cabinets;
two first incoming line cabinets on the 10kV I-section bus and the 10kV II-section bus as two incoming lines of a power distribution module are respectively connected with the power supply or the power distribution module at the upper stage of the power supply, and two second incoming line cabinets on the 10kV I-section bus and the 10kV II-section bus as two feeder lines of the power distribution module are respectively connected with the power distribution module at the lower stage or the four-end flexible straight module; feeder cabinets on the 10kV I section bus and the 10kV II section bus are used as outgoing lines and are respectively connected with the user side.
6. A medium voltage distribution network double loop topology comprising four port flexible switches according to claim 3, characterized in that: the primary main wiring of the distribution room comprises a 10kV I section bus, a 10kV II section bus, two sections of 10kV independent buses, a 0.4kV I section bus, a 0.4kV II section bus, a 0.4kV III section bus and four sections of 0.4kV independent buses, wherein the two sections of the 10kV II section bus are the 10kV I section bus;
each section of the 10kV independent bus is provided with two transformer cabinets, an incoming line cabinet and a feeder line cabinet; the two incoming line cabinets on the 10kV I-section bus and the 10kV II-section bus are used as two incoming lines of a power distribution module and are respectively connected with the power supply or an upper-level power distribution module thereof, and the two feeder line cabinets on the 10kV I-section bus and the 10kV II-section bus are used as two feeder lines of the power distribution module and are respectively connected with a lower-level power distribution module or the four-end flexible straight module thereof; the two transformer cabinets are respectively connected with the 0.4kV independent bus to supply power to the 0.4kV independent bus;
each section of the 0.4kV independent bus is provided with an incoming line main cabinet, a capacitor cabinet, an outgoing line cabinet and a contact cabinet;
the contact cabinet of the 0.4kV I-section bus is connected with the 0.4kV II-section bus to form a group, the incoming line main cabinet of the 0.4kV I-section bus is connected with the transformer 1 cabinet of the 10kV I-section bus of the distribution room, and the incoming line main cabinet of the 0.4kV II-section bus is connected with the transformer 2 cabinet of the 10kV II-section bus;
the contact cabinet of the 0.4kV section III bus is connected with the 0.4kV section IV bus to form a group, the incoming line main cabinet of the 0.4kV section III bus is connected with the transformer 3 cabinet of the 10kV section I bus in the distribution room, and the incoming line main cabinet of the 0.4kV section II bus is connected with the transformer 4 cabinet of the 10kV section II bus;
and the outgoing line cabinet of each 0.4kV independent bus is connected with the user side.
7. The dual ring topology of a medium voltage distribution network comprising a four-port flexible switch according to claim 1, wherein: the cable module adopts a crosslinked polyethylene insulated polyvinyl chloride sheath power cable, the material of the cable conductor adopts a copper conductor, the cable insulation shield or the metal sheath adopts a soft copper wire or a copper strip, the cable core has 3 cores, and the cross section comprises 300mm2And 400mm2The laying mode comprises a calandria and a cable tunnel.
8. The dual ring topology of a medium voltage distribution network comprising a four-port flexible switch according to claim 7, wherein: the calandria laying mode is as follows: tamping raw soil at the bottom of the pipe, paving a C15 concrete bottom plate on the pipe, arranging the calandria on the bottom plate side by side, arranging a communication pipe between every two calandrias at one side of the two calandrias, backfilling the calandria by fine sand, and arranging a warning belt on the piping;
the cable tunnel laying mode is as follows: the method comprises the steps of excavating a cable tunnel clearly, arranging two side brackets in the cable tunnel, wherein each side bracket comprises a plurality of layers of cable brackets, embedded parts and an inner connection zone, wherein each layer of cable bracket is connected with each embedded part through bolts, and the inner connection zone is connected with each layer of cable bracket and is grounded.
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| CN111614053B (en) * | 2020-06-01 | 2021-01-26 | 国网重庆市电力公司市北供电分公司 | Power supply circuit |
| CN112003183B (en) * | 2020-08-06 | 2021-08-10 | 河南省同信电力工程有限公司 | Power transmission network fault processing system and method |
| CN117117875B (en) * | 2023-10-23 | 2024-01-26 | 广东电网有限责任公司佛山供电局 | Power grid system control method, device, equipment and medium |
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